Oyster Shell Investigation

Press, Volume CIX, Issue 32303, 22 May 1970, Page 24

Oyster Shell Investigation

(From Our Own Reporter)

WELLINGTON, May 21.

An investigation to show clearly whether the return of oyster shell to the Foveaux Strait oyster beds was beneficial was being undertaken, the Secretary for Marine (Mr R. Kerr) said today.

He said there had been much discussion on whether the shells should be returned to the beds after the oysters had been opened in the factories.

“But departmental scientists believe this would be beneficial in several ways,” he said.

Departmental scientists considered that tiny spat and wingers on the shell would survive the experience and continue to grow when returned to the beds. They also considered that the newly-opened shell would be suitable for spat settlement and would result in better breeding success by the oysters. in addition, the dead shell would consolidate the bottom sediments and make conditions in the straits better for the oysters. He said an experiment had commenced to show clearly whether or not' the return of shell would be beneficial. A boat had been chartered and four divers were setting up the experiment, which consisted of marking out a 50yd by 50yd square on the sea bed off Bird Island in about 10 fathoms of water. One thousand sacks of newly opened shell would be laid inside this square. The number of spat and wingers on the shells would be checked at two monthly intervals. The number of spat and wingers surviving 'and growing and the numbers

of new spat settling on the shell would show whether or not the return of shell was worth while. “Further experiments on matters related to the return of shell are also planned and it is hoped that an answer to this problem will be obtained within a year,” Mr Kerr said.